The present invention relates generally to livestock handling systems. More particularly, the present invention relates to an automated livestock sorting system for identifying and sorting livestock.
Livestock sorting systems are used in dairy harvesting facilities to identify and sort dairy cows so that specific, identified cows can receive special handling, such as periodic medical examination or treatment, isolation from other livestock, or combination with livestock having similar characteristics, including milk production or milk let-down curves. Typically, these livestock sorting systems are connected to a milking parlor, and the cows are sorted as they leave the parlor after milking has been completed. Conventional livestock sorting systems include an alley having an entrance, a main exit, and a sort exit. An air-driven gate is positioned in the alley for movement between a sorting position, in which the gate blocks the main exit and opens the sort exit, and a non-sorting position, where the gate blocks the sort exit and opens the main exit. Typically, as shown in U.S. Pat. No. 4,798,175 (xe2x80x9cthe ""175 patentxe2x80x9d), and U.S. Pat. No. 5,183,008 (xe2x80x9cthe ""008 patentxe2x80x9d), the livestock sorting system utilizes a pneumatic circuit for actuating the gate and includes an air-piloted spool valve for controlling the operation of the gate.
An electronic identification system such as that disclosed in the ""175 and ""008 patents is typically provided at or near the entrance of the alley for sensing the presence of cows in the alley and for providing an electric signal when a xe2x80x9csort cowxe2x80x9d is present. Each cow wears a transponder that is detected by an antenna as the cows pass through the entrance of the alley. When a sort cow is detected by the identification system, an electric signal is provided that interfaces with the pneumatic circuit to generate a fluid signal that triggers the spool valve to move the gate into the sorting position.
Once the gate has been opened to the sorting position, it can be closed in several ways. For example, the ""175 patent provides a one-way gate in the sort exit that includes a pneumatic switch that is actuated when an animal pushes the one-way gate to the open position as the animal passes through the sort exit. The ""008 patent provides a pneumatic exit switch, such as a trip wand, that is mounted on the sort gate and is actuated by contact with the animal as it passes through the sort exit. Either way, the pneumatic signal from the switch is delivered to the spool valve to move the gate to the non-sorting position.
The pneumatic livestock sorting systems exemplified by the ""175 and ""008 patents are complex, requiring an extensive pneumatic network, and are difficult to install and maintain. Moreover, it is difficult to control and coordinate several of these pneumatic systems from a remote location. Further, it is difficult to efficiently sort livestock using a pneumatic system due to the inherent lag time required for a pneumatic control to respond to a command.
Some of these problems were addressed by livestock sorting systems having an electrical gate actuating system. U.S. Pat. No. 5,628,284 (xe2x80x9cthe ""284 patentxe2x80x9d) discloses a livestock cutter gate apparatus utilizing a solenoid-driven spool valve to open and close the sort gate.
However, whether a livestock sorting system is pneumatic or electrical, the major challenge in designing a sorting system is to allow for smooth livestock flow. If the sorting system does not allow for smooth cow flow, cows can xe2x80x9cback upxe2x80x9d at the sorting system, creating problems in both upstream and downstream operations. Moreover, the system should be designed to avoid (1) sorting cows that should not be sorted or (2) not sorting cows that should be sorted. Obviously, errors in the sorting process defeat the rationale for having a sorting system in the first place.
Typically, errors in sorting are caused by fast moving cows following closely behind a lead cow. If sort gate is opened for the lead cow, the following cow may attempt to enter the sort exit before the gate closes, regardless of whether it is a sort cow. Likewise, if the lead cow is not a sort cow and the second cow is a sort cow, the gate may not open in time to sort the second cow.
These problems have been addressed in various ways. The cutter gate apparatus of the ""284 patent provides a pair of saloon gates located at the entrance of the alley. If a cow is identified as a sort cow, the saloon gates are closed until such time that the sort cow has entered the sort exit and pushed open the exit gate, causing the sort gate to close. In this manner, the problem of sorting a xe2x80x9cnon-sortxe2x80x9d cow is avoided. However, where the sort cow is slow-moving, the use of saloon gates can stop cow flow, with cows backing up at the saloon gates. Further, the use of saloon gates doubles the amount of mechanical controls necessary to operate the sort gate, requires timing devices to activate both gates simultaneously, and doubles the number of potential xe2x80x9cpinch pointsxe2x80x9d where the animal or operator can be injured.
The sort gate of the ""008 patent utilizes an air-piloted spool valve having two pressurized air inputs as an override device. One input causes the gate to close, while the other causes the gate to open. If pressurized air is supplied to both inputs, i.e., both a gate open and a gate close signal are given, the gate remains open. Thus, if a second sort cow has been identified before a first sort cow has entered the sort exit and tripped the exit switch, when the first cow does trip the exit switch pressurized air will be provided at both ports of the spool valve, with the result that the sort gate remains open. Again, however, this is a pneumatic system and suffers from the same infirmities discussed above with respect to pneumatic systems generally. Moreover, use of an air-piloted spool valve results in a system that is overly dependent on the cleanliness of the air supply and proper lubrication for its operation, and hence is prone to reliability problems when used in a livestock environment.
Further, none of the prior art sort gates have safety features that can prevent injuries to livestock and to dairy personnel in the event a gate closes prematurely.
What is needed is a safe livestock sorting system having an electrically actuated gate that is controlled by an activity-based controller in a manner to ensure smooth cow flow and to minimize sorting errors. What is also needed is a livestock sorting system that can be operated and monitored from a location remote from the sorting system itself, and is able to interface with other dairy harvesting facility operations that may indicate or otherwise identify cows to be sorted. What is further needed is a system that is less complex and easier to maintain and operate than prior art livestock sorting systems. Finally, there is a serious need for a livestock sorting system that reduces or avoids injury to livestock and dairy personnel in the event a sort gate closes prematurely.
These needs are met by the livestock sorting system of the present invention.
The livestock sorting system of the present invention comprises (a) an alley comprising an entrance, a main exit and a sort exit, (b) a sort gate positioned in the alley between the main exit and the sort exit, the sort gate being shiftable between a sorting position in which the sort gate blocks the main exit and opens the sort exit, and a non-sorting position in which the sort gate blocks the sort exit and opens the main exit, (c) an entrance sensor, (d) an activity-based controller, (e) a sort gate activator, and (f) an exit sensor. The entrance sensor identifies individual livestock entering the alley and provides an identification signal to the activity-based controller for each animal. The activity-based controller compares the identification signal to a database comprising identification of cows to be sorted. If the identification signal corresponds to a specific animal identified as a sort cow in the database, the activity-based controller sends a sort signal to a sort gate activator.
Upon receipt of the sort signal from the activity-based controller, the sort gate activator sends a gate open signal, thereby causing the sort gate to shift to the gate open position. As the sort cow enters the sort exit, it passes the exit sensor, which provides an exit signal to the sort gate activator. When the sort gate activator receives the exit signal, it checks whether it has received a sort signal from the activity-based controller indicative of an additional animal to be sorted. If no such signal has been received, the sort gate activator provides a gate close signal, thereby causing the sort gate to shift to the non-sorting position. If, on the other hand, the sort gate activator has received an additional sort signal from the activity-based controller, no gate close signal is sent, and the sort gate remains in the sorting position.
The sort gate activator includes an accumulator function, or is connected to an accumulator device. The accumulator function or accumulator device has a predetermined gate close value that is incremented by a predetermined counting value when the sort gate activator receives a sort signal from the activity-based controller. When an exit signal is received from the exit sensor, the accumulator function or device decrements the same counting value. If decrementing the counting value results in the predetermined gate close value being obtained, the sort gate activator sends a gate close signal. Otherwise, no gate close signal is sent.
The livestock sorting system of the present invention provides for smooth livestock flow, and substantially eliminates sorting errors. Since the system of the present invention is electrical, rather than pneumatic, it is less complex, easier to install and operate, and more responsive than the prior art pneumatic systems exemplified in the ""175 and ""008 patents. The system of the present invention further results in improved cow flow over the livestock cutting apparatus of the ""286 patent, since no saloon gates are needed to reduce sorting errors. Moreover, additional sort gate systems can easily be added for additional sort functions.
The livestock sorting system of the present invention also can adapt to individual livestock parameters, such as the speed at which an individual animal moves at specific points in time and therefore can be used to optimize livestock flow through a facility by opening and closing gates based on each individual animal""s rate of speed.
Therefore, it is an object of the present invention to provide a livestock sorting system that allows for smooth animal flow and substantially eliminates sorting errors.
It is an additional object of the present invention to provide a livestock sorting system that is easy to install and operate, less complex and more responsive than currently available systems.
It is a further object of the present invention to provide a system that can be operated from a remote location.
It is yet an additional object of the present invention to provide a system that can be operated in conjunction with additional livestock sorting systems or other dairy harvesting operations for a remote location.
It is yet another object of the present invention to provide a system that can adapt to individual livestock parameters, such as rate of speed, and can customize gate opening and closing for each animal, thereby resulting in seamless animal flow.
Further objects, features, and advantages of the present invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings.